/*-
 * SPDX-License-Identifier: BSD-2-Clause
 *
 * Copyright (c) 2008 Isilon Inc http://www.isilon.com/
 * Authors: Doug Rabson <dfr@rabson.org>
 * Developed with Red Inc: Alfred Perlstein <alfred@freebsd.org>
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 */

#include <sys/_iovec.h>

#define ETYPE_NULL              0
#define ETYPE_DES_CBC_CRC       1
#define ETYPE_DES_CBC_MD4       2
#define ETYPE_DES_CBC_MD5       3
#define ETYPE_DES3_CBC_MD5      5
#define ETYPE_OLD_DES3_CBC_SHA1 7
#define ETYPE_DES3_CBC_SHA1     16
#define ETYPE_AES128_CTS_HMAC_SHA1_96 17
#define ETYPE_AES256_CTS_HMAC_SHA1_96 18
#define ETYPE_ARCFOUR_HMAC_MD5  23
#define ETYPE_ARCFOUR_HMAC_MD5_56 24

/*
 * Key usages for des3-cbc-sha1 tokens
 */
#define KG_USAGE_SEAL           22
#define KG_USAGE_SIGN           23
#define KG_USAGE_SEQ            24

/*
 * Key usages for RFC4121 tokens
 */
#define KG_USAGE_ACCEPTOR_SEAL  22
#define KG_USAGE_ACCEPTOR_SIGN  23
#define KG_USAGE_INITIATOR_SEAL 24
#define KG_USAGE_INITIATOR_SIGN 25

struct krb5_key_state;

typedef void init_func(struct krb5_key_state *ks);
typedef void destroy_func(struct krb5_key_state *ks);
typedef void set_key_func(struct krb5_key_state *ks, const void *in);
typedef void random_to_key_func(struct krb5_key_state *ks, const void *in);
typedef void encrypt_func(const struct krb5_key_state *ks,
    struct mbuf *inout, size_t skip, size_t len, void *ivec, size_t ivlen);
typedef void checksum_func(const struct krb5_key_state *ks, int usage,
    struct mbuf *inout, size_t skip, size_t inlen, size_t outlen);

struct krb5_encryption_class {
        const char              *ec_name;
        int                     ec_type;
        int                     ec_flags;
#define EC_DERIVED_KEYS         1
        size_t                  ec_blocklen;
        size_t                  ec_msgblocklen;
        size_t                  ec_checksumlen;
        size_t                  ec_keybits;     /* key length in bits */
        size_t                  ec_keylen;      /* size of key in memory */
        init_func               *ec_init;
        destroy_func            *ec_destroy;
        set_key_func            *ec_set_key;
        random_to_key_func      *ec_random_to_key;
        encrypt_func            *ec_encrypt;
        encrypt_func            *ec_decrypt;
        checksum_func           *ec_checksum;
};

struct krb5_key_state {
        const struct krb5_encryption_class *ks_class;
        volatile u_int          ks_refs;
        void                    *ks_key;
        void                    *ks_priv;
};

extern struct krb5_encryption_class krb5_aes128_encryption_class;
extern struct krb5_encryption_class krb5_aes256_encryption_class;

static __inline void
krb5_set_key(struct krb5_key_state *ks, const void *keydata)
{

        ks->ks_class->ec_set_key(ks, keydata);
}

static __inline void
krb5_random_to_key(struct krb5_key_state *ks, const void *keydata)
{

        ks->ks_class->ec_random_to_key(ks, keydata);
}

static __inline void
krb5_encrypt(const struct krb5_key_state *ks, struct mbuf *inout,
    size_t skip, size_t len, void *ivec, size_t ivlen)
{

        ks->ks_class->ec_encrypt(ks, inout, skip, len, ivec, ivlen);
}

static __inline void
krb5_decrypt(const struct krb5_key_state *ks, struct mbuf *inout,
    size_t skip, size_t len, void *ivec, size_t ivlen)
{

        ks->ks_class->ec_decrypt(ks, inout, skip, len, ivec, ivlen);
}

static __inline void
krb5_checksum(const struct krb5_key_state *ks, int usage,
    struct mbuf *inout, size_t skip, size_t inlen, size_t outlen)
{

        ks->ks_class->ec_checksum(ks, usage, inout, skip, inlen, outlen);
}

extern struct krb5_encryption_class *
        krb5_find_encryption_class(int etype);
extern struct krb5_key_state *
        krb5_create_key(const struct krb5_encryption_class *ec);
extern void krb5_free_key(struct krb5_key_state *ks);
extern struct krb5_key_state *
        krb5_derive_key(struct krb5_key_state *inkey,
            void *constant, size_t constantlen);
extern struct krb5_key_state *
        krb5_get_encryption_key(struct krb5_key_state *basekey, int usage);
extern struct krb5_key_state *
        krb5_get_integrity_key(struct krb5_key_state *basekey, int usage);
extern struct krb5_key_state *
        krb5_get_checksum_key(struct krb5_key_state *basekey, int usage);